Refrigerating apparatus



July 16, 1935- w. c. HoLBRooK REFRIGERATING APPARATUS ginal Filed Nov.50, 1929 #VM IN VENT 0R A TT ORNE Y Patented July 1e, 193sv 2,008,325.

lUNITED STATES PATENT oFFlcE REFRIGERATING APPARATUS William C.Holbrook, Dayton, Ohio, assignor, by

mesne assignments, to General Motors Corporation, a corporation o!Delaware Application Nevember so, 1929, serial No. 410,162 Renewed'June"l, 1934 4 Claims. (Cl. 20-35) 'I'his invention relates to refrigeratingappaa molded piece of hard blown rubber 26. This ratus and especially tothe construction for the piece of rubber may be formed in several ways,a closure elements in the refrigerator cabinet. l preferred form ofwhich is to utilize a gas to ex- An object of this invention is toreduce the pand the interior structure of the rubber into the 5 thermalconductivity of a cabinet around the cellular structure disclosed in thedrawing. The' 5 door or access opening of the cabinet. rubber is thenhardened and a smooth hard shell Another object of the invention is toprovide or crust 21 formed on its exterior. All odors and a closuremember for a refrigerator cabinet that excess gas have of course beenremoved from the shall be lighter in construction, made of betterrubber. This piece of rubber is molded in the l0 insulation, that doesnot absorb moisture, and specific shape desired for the door. This hardlo which is very easily assembled, blOWn. rubber S 0f better insulationthan that Further objects and advantages of the present generally usedfor the doors of a refrigerator invention will be apparent from thefollowing cabinet and furthermoreismuch lighter and does description,reference being had to the accomnot absorb moisture.

panying drawing, wherein a preferred form of A metal member 28 and screwretaining mem- 15.

the invention is clearly shown. l bers 29 are preferably molded in withthe rubber In the drawing: to provide suitable fastening means for thescrews Fig. 1 is a front view of a cabinet to which the 38 of thehinges.

invention may be applied. The inner casing member 30 of the door may beFig. 2 is a cross sectional view of the hinged of any suitable materialbut itispreferied to have 20 side 0f the door construction, this casingmember 30 0f a substantially Self Fig. 3 is a cross sectional view ofthe opposite sustaining sheet or sheets of organic material.

edge of the door from that shown in Fig. 2. More SIJeCcally it may beformed 0f Cellulose Fig. 4 is a view of a seal which may be usedderivatives such as any suitable nitro-cellulose around the edge of thedoor as disclosed in Figs. product, and preferably one of the pyroxylin25 2 and 3. compounds. A specific pyroxylin compound Fig. 5 is amodification of Fig. 4. which has been found to be satisfactory is oneThe refrigerator cabinet embodying features known in the trade asPyralin. kA preferred of this invention may be if desired a mechanicalImethodvof placing this casing member on the refrigerator cabinet of thetype disclosed in the cover or door 'is to soften the member 30 by any30 application of Henry P. Braeutigam and Wm. C. suitable method ormeans and to then apply it to Holbrook S., N. 257,989 filed Feb. 28,1928. The the cover or door frame andto curl it around the constructionaround the door or access .opening projecting beads as indicated at 32and at 33. may be slightly modified in order to produce a After thecasing member 30 has been applied to 35 construction of minimum heatconductivity. In the insulation a suitable seal 34 having a beaded 35order to produce this minimum of heat conducportion may be placed at theedges 32, 33 and then tivity the metal parts of the opening cover ordoor the metal panel 20 may be applied to the cover or and the access ordoor opening molding are redoor. Preferably the edge away from thehinges duced considerably. As disclosed inffFig. I2 the is madeV asshown in Fig. 3 and th'e other vthree front metal panel of the cabinetis indicated as 20. edges of the door and metal panel are shaped as 40The main door jamb may be constructed of some shown in Fig. 2. That is,the metal panel 20 is relatively non-conducting material such as woodprovided with one edge having a circular or inand one portion thereof isindicated as 2 I. VMem wardlybentl flange 35 and is provided with threebers corresponding to members 20 and 2| extend substantially straightflanges 36 on the other completely around the door opening. On oneedges. .Thepanell or casing member 20 may thus 45 side of the dooropening one or more hinges 22 be applied ilrst to the edge as shown inFig. 3 may be attached to the cabinet body proper and and then the outercasing panel may be swung also to the door. The inside ofthe cabinetmayV about that as a pivot and may be placed over the be provided with alining 24 preferably of porceremainder of the frame. 'I'he outer casingmemlained sheet metal which forms the, food comber'20 may then besecuredby Aany suitable means 50 l partment of the refrigerateL cabinet 23. Amoldsuch as by the screws 38 which also secure lthe ing 25 may be placedinside of the door jamb 2| hinge or hinges 22 to the door. in order topresent a neat appearance at the do'or 'I'he lining member 30 may besoftened by any e opening. suitable method or methods. One method is toThe interior structure of the-door is preferably place the material inthe softening solution such 55 as one consisting of one part acetone andthree parts of water. After the member 30 has remained in the solutionsufficiently long to become sufficiently appliable it may be applied tothe door frame preferably first by applying l a coat of cement to theside of the lining? member 30 adjacent the frame. The lining member 30is then curled around the cover or door. If necessary the corners ofmember 30 may be cut in order to provide a proper fit of the liningmember to the frame and the edges thus formed may be cemented togetherby any suitable cement adapted to adhere to this material and aft'er thecement has dried the edge may be finished by any method such as by sandpapering and bufilng.

The material forming the lining member 30 may be softened by any methodother than by dipping in solution. 'I'hus any type of vapor which maysoften the material may be yused for the necessary length of time. Thusmethyl acetone may be suspended in any suitable solvent and the liningmaterial and the acetone with the solvent may be placed in a compartmentmaintained at a temperature suflicient to create the necessary vapor inthe compartment to soften. the material.

In the construction of the cover or door it is to be understood that nolcements or other material should be used at temperatures which-maycreate a fire hazard due to the inflammability of the lining member 21.

'I'he access or door opening may be provided with a molding 25 which maybe made in accordance with the method disclosed for the cover or door.Thus the molding may include one or more members made of the same kindof rubber material and covered with material 30a of the same characterwith the material of lining member 30 of the door. This molding may besecured to the access or door opening yjamb by any suitable means suchas by the screws 31.

It is to be noted that the seal 3l prevents contact of the lining member30 with any portion of the access or door opening. Thus damage to themember 3U is prevented.

It is to be understood that features of this invention include shapesother than a rectangular door. Thus circular, oblong or other shapedinsulated lids may be made in accordance with this invention. The frameinstead of being rectangular may be made circular in the well knownmanner.

When it is desired to provide a seal adapted to beplaced on the cover ordoor without the use of a large number of staples or tacks laconstruction such as shown in Figs. 2, 3 and 4 or 5 may be used. Thus aseal may be provided with a contact head 40 preferably of cotton and anattaching bead 4| preferably of ltwisted paper. Preferably this seal isformed by starting a waterproof tape IZpreferably of rubber adjacent oneof the largeends and extending it to the opposite end, bending itaroundthe enlarged opposite end, returning to the first end, and bendingit around this first, enlarged end, and returning it again to theopposite end. 'I'his construction provides a waterproof covering forboth ends 40 and 4I and also provides a three ply connecting-portionbetween the two ends. This three ply portion makes the seal very strong.This three ply portion is of course stitched together adjacent each ofthe adjacent enlarged ends. The grooved flange 35 is adapted to pinchthe bead 4| as shown in Fig. 3 and the shape of the insulation and thestraight flange 36 are such as to pinch the bead 4I as shown in Fig. 2.Thus the seal may be attached to the door with only a temporary type offastening. staple or with no staple at all.

It will be noted that the structure disclosed is formed of betterinsulation than that generally used and is also lighter in constructionand furthermore does not absorb moisture. As the insulation is molded inone piece and has preferably only an inner casing member and outercasing memberwith afseal pinchedvbetween them the door constructiorrisvery simply and easily assembled due to its very few parts. Furthermoreit is noted that due to the thickness of the Pyralin inner casing member30 that there will be very small heat leakages therethru to causesweating on the surface members of the cabinet as has hitherto been theexperience where thicker metal members were used in place of the Pyralininner casing member. f

If preferred,vthe Pyralin 30 may be preformed into the shape of the doorand applied to the blown rubber, also previously formed, by a exiblediaphragm such as is more particularly described in the copendingapplication of Carl Clifford Ritter for Refrigerating apparatus, DocketF-2249 executed November\22, 1929, S. N. 410,854, filed November 30,1929.

While the form of embodiment of the invention as herein disclosedconstitutes a preferred form, it is to be understood that other formsmight be adopted, all coming within the scope of the claims whichfollow.

What is claimed is as follows:

1. -A closure member for refrigerator cabinets comprising a blown rubberinsulation, a metallic casing member for one portion of said insulationand a pyroxylin compound casing member for another portion of saidinsulation. 2. A door for refrigerator cabinets comprising a blownrubber insulation having a hard crust, said insulation being formed intothe shape of a refrigerator door and casing members formed of thinsheets tting over said formed insulation to provide an outer surface forthe door.

3. A refrigerator cabinet wall structure comprising a blown rubberinsulation having a hard crust, said insulation beingformed into theshape of the wall structure desired and casing members formed otthinsheets fitting over said formed insulation to provide an -outersurface for the wall structure.

4. An insulating structure comprising a blown rubber insulation having ahard crust, and a nishing sheet overlying and being bonded to thesurface of the hard crust of the blown rubber insulation.

WILLIAM C. HOLBROOK.

